We propose to study the alterations of tumor-specific immunity produced by cancer chemotherapy in man. We will obtain tumor material by biopsy from patients before chemotherapy and will cultivate part of the cells in vitro, storing the remainder at -70 degrees C. Serum, peripheral blood lymphocytes and monocytes will be obtained from each patient before, during and at weekly intervals after chemotherapy. The patient's clinical response to therapy will also be measured objectively. Lymphocyte-mediated cytotoxicity to the tumor will be measured by incubating lymphocytes and autochthonous (or allogeneic) tumor cells in flat-bottom plastic trays for 48 hours, after which direct enumeration or counting of radioactively labeled tumor cells will be performed. Blocking factor will be determined by incubating serum and tumor cells before testing lymphocyte-mediated cytotoxicity. Cytophilic antibodies will be titrated by allowing mouse monocytes to adhere to glass on Lab-Tek Chamber/Slides, adding dilutions of putative antiserum from the patient, and after washing off excess serum, adding tumor target cells. Integrity of monocyte receptors for cytophilic antibody will be tested by using human monocytes and adding proved cytophilic antibodies to the chamber before target tumor cells are put into the system. By performing these studies serially after chemotherapy as well as during the period of administration of drugs, we hope to discern whether immunity to the tumor is suppressed by our current regimens, or whether beneficial effects on immunity occur as a result of their tumoricidal activity. BIBLIOGRAPHIC REFERENCES: Friedlaender, G. E. and Mitchell, M. S. A virally induced osteosarcoma in rats. A model for immunological studies of human osteosarcoma. J. Bone and Joint Surg. 58-A: 295-302, 1976. Lundberg, W. B. and Mitchel, M. S. Transient warm autoimmune hemolytic anemia and cryoglobulinemia associated with seminoma. Yale J. Biol. Med., 50: In press, 1977.